Good thing he is just wanting to do it kind of as a hobby (Sounds like). His time is the biggest obstacle in the mark up. It will be difficult to make much on them. But if it just kind of for fun and you can get your name out there and break even in the beginning or make 10%. Then he can build a little clientele, and maybe get a little more out of his work in the future. His name would make for a good laser etch in the body. Something in the 1 to 2000 lumen with green and red filtered lenses for the hunter. 
I would personally shy away from it. Maybe build some stuff for friends and family.